Since we are on the topic of best condtioners, this seems like a good time to quote what museum conservators say about preserving leather. They have different goals than we do. They want the objects to last as long as possible, but they do not "use" them at all. No one would be permitted to put on a pair of museum shoes, let alone walk around in them or expose them to the elements. That said, the conservator's view of leather dressings is uniformly negative. This is from...

I use microfiber cloth for shoes. Softer than cotton (don't know whether this matters), cleans easily, and so cheap that it does not matter that I had to buy them. Auto shops sell them in bunches for car finishing.

Fascinating. I have at times spent more on repairs of some shoes than it would have cost to replace them. This happened because they were no longer wearable, but I could not bring myself to throw away shoes that could be saved.
Another reason I don't buy expensive shoes. If I had such possessions, I would not be able to make a business decision to discard them when a repair by an expert shoemaker would extend their lives.
Glad to know there are people out there who...

Can DW or someone explain why there would be a need, or a point, to replace the insole? Protected as it is by the uppers and outsole, does the insole ever outlive the upper? It would seem more likely that the insole would be in good shape while the uppers, exposed to the elements as they are, deteriorated beyond repair.
Since replacing the insole also means destroying the footbed that has developed, why would someone do it if they did not have to?
Do uppers ever...

Easy to imagine you having that problem. If DW were to make shoe trees, they would be works of art. The would probably be worth the price to people who would buy his bespoke products in the first place.

DW,
I was interested in your comment that you cannot get lasted shoe trees. I understand if you mean that you cannot find a last maker who will make trees at the same time as the lasts, and I gather last makers are hard to come by anyway.
I would have thought that there would be a middle ground between off the shelf shoe trees and those made by the maker of the last. Call them "fitted" shoe trees. Made to conform to the shape of the shoe better than a generic tree,...

DW,
Thanks for the informative post on what stretching does. I don't have any bespoke shoes. If I did, I would never consider stretching them myself. If they needed any adjustments, I would leave that to the maker.
As I said, I don't have any shoes that NEEDED stretching. But I do have some that, after wearing for a while, are still tighter in the toes than I would like. So I stretch.

I have stretched some shoes myself. I have not had any disasters, but lots of anxiety. I have stopped using the strecther and instead got a pair of shoe trees with a very strong spring pressing the two halves apart. The spring is strong enough that it takes quite a bit of pushing to get the trees into the shoe. Once there they push the two sides apart, very firmly, but not nearly as hard as a stretcher can do. I don't use stretching fluid. I did not have any real problems...

If it is largely due to grit, then gently removing it should cut the risk.
Still puzzled why cracking seems so rare in things like gloves, some of which live fairly hard lives.
DW, from your experience with working cowboy boots, did you see a difference in longevity based on how carefully a client maintained his footwear?

DW,
Are wallets made from thinner, softer, more flexible leather than shoes? Come to think of it, what about gloves? I have some gloves and mitts that are decades old, treated with Snoseal to protect from water, and no cracking. Never polished or stripped, of course.
How does leather in other applications hold up? Bookbindings live their lives indoors, no exposure to the elements, indoor dust, gentle handling, etc. But eventually they crack.
Could much of the difference...